Specifications

Power Train Testing and Adjusting 42
Problem: Pressure to one clutch is low.
Probable cause:
1. Clutch piston seal alignment is not correct, oil leaks
through.
2. Seal rings on shaft or clutch piston seals are broken
or worn.
3. Modulating valve assembly stuck.
Problem: Low pump pressure.
Probable cause:
1. Low oil level.
2. Main relief valve movement is restricted.
3. Transmission oil pump is worn.
4. Inner oil leakage.
5. Main relief valve not adjusted properly.
Problem: Low lubrication pressure or no
lubrication pressure.
Probable cause:
1. Low oil pressure or no oil pressure caused by:
a. Failure of the oil pump or a defect in the oil
pump.
b. Restriction in the oil flow circuit such as a dirty
oil screen.
c. Inching valve reducing spool stuck open.
d. Leakage inside of transmission caused by com-
ponent defects.
2. Oil cooler has restriction to oil flow.
Problem: High lubrication pressure.
Probable cause:
1. Restricted external oil lines or internal passages.
2. External oil lines are not connected correctly.
Problem: High converter charge pressure.
Probable cause:
1. A plugged converter bypass orifice.
2. A restriction inside the converter assembly.
3. A plugged oil flow passage.
Problem: Low converter charge pressure.
Probable cause:
1. Converter relief valve stuck open.
2. Main relief valve movement is restricted.
Problem: Low converter outlet pressure or cooler
inlet pressure.
Probable cause:
1. Low oil pressure.
2. Cooler relief valve stuck open.
Problem: High converter outlet pressure or cooler
inlet pressure.
Probable cause:
1. Restriction in oil cooler lines or a plugged oil
cooler.
Problem: Low stall speed.
Probable cause:
1. Engine performance is not correct.
2. The one-way clutch of the torque converter does
not hold.
Problem: High stall speed in both directions.
Probable cause:
1. Low oil level.
2. Air in the oil.
3. Clutches slip (clutch plates slide in relation to one
another).
4. Torque converter failure.